Class 12 Biology – Biotechnology : Principles and Processes Notes

Class 12 Biology – Biotechnology : Principles and Processes Notes

Biotechnology: Principles and Processes – Short Notes

1. Introduction to Biotechnology

  • Biotechnology: Use of living organisms, cells, or biomolecules to develop useful products and processes.
  • Two core techniques:
    1. Genetic Engineering
    2. Bioprocess Engineering

2. Principles of Biotechnology

A. Genetic Engineering

  • Direct manipulation of DNA to alter genetic makeup.
  • Involves:
    • Isolation of DNA
    • Cutting DNA using restriction enzymes
    • Inserting gene into vector
    • Transferring recombinant DNA into host

B. Bioprocess Engineering

  • Use of microorganisms in large-scale production.
  • Carried out in bioreactors under controlled conditions.

3. Tools of Recombinant DNA Technology

A. Restriction Enzymes

  • Act as molecular scissors.
  • Cut DNA at specific recognition sites.
  • Example: EcoRI.

B. Cloning Vectors

  • DNA molecules used to carry foreign gene.
  • Common vectors:
    • Plasmids
    • Bacteriophages

Features of vectors:

  • Origin of replication (ori)
  • Selectable marker
  • Cloning site

C. Competent Host

  • Organism that receives recombinant DNA.
  • Usually bacteria like E. coli.

4. Steps in Recombinant DNA Technology

  1. Isolation of genetic material (DNA)
  2. Cutting DNA with restriction enzymes
  3. Amplification of gene (PCR – Polymerase Chain Reaction)
  4. Ligation into vector
  5. Transfer into host cell
  6. Selection of transformants
  7. Production of desired product

5. Polymerase Chain Reaction (PCR)

  • Technique to amplify specific DNA sequences.
  • Requires:
    • Template DNA
    • Primers
    • DNA polymerase
    • Nucleotides
  • Steps:
    • Denaturation
    • Annealing
    • Extension

6. Bioreactors

  • Large vessels used for mass culture of microbes.
  • Provide optimal conditions (pH, temperature, oxygen).
  • Types:
    • Stirred tank bioreactor
    • Airlift bioreactor

7. Downstream Processing

  • Separation and purification of final product.
  • Includes:
    • Extraction
    • Purification
    • Quality testing

Biotechnology: Principles and Processes | MCQs

1. Introduction to Biotechnology

  1. Biotechnology mainly involves the use of:
    a) Machines only
    b) Living organisms or their components
    c) Chemicals only
    d) Metals
    Answer: b) Living organisms or their components
  2. The two core techniques of biotechnology are:
    a) PCR and cloning
    b) Genetic engineering and bioprocess engineering
    c) Mutation and evolution
    d) Selection and breeding
    Answer: b) Genetic engineering and bioprocess engineering

2. Tools of Recombinant DNA Technology

  1. Restriction enzymes are also known as:
    a) Ligases
    b) Molecular scissors
    c) Polymerases
    d) Vectors
    Answer: b) Molecular scissors
  2. EcoRI recognizes a:
    a) Random DNA sequence
    b) Specific DNA sequence
    c) RNA sequence
    d) Protein sequence
    Answer: b) Specific DNA sequence
  3. The sticky ends are produced by:
    a) DNA polymerase
    b) Restriction endonucleases
    c) Ligase
    d) RNA polymerase
    Answer: b) Restriction endonucleases
  4. A plasmid is commonly used as a:
    a) Host
    b) Vector
    c) Enzyme
    d) Antibiotic
    Answer: b) Vector
  5. The origin of replication (ori) helps in:
    a) Cutting DNA
    b) DNA replication inside host
    c) Protein synthesis
    d) Cell division
    Answer: b) DNA replication inside host
  6. Selectable markers are used to:
    a) Cut DNA
    b) Identify transformed cells
    c) Replicate DNA
    d) Produce enzymes
    Answer: b) Identify transformed cells
  7. The host commonly used in recombinant DNA technology is:
    a) Virus
    b) Human cell
    c) Escherichia coli
    d) Fungi
    Answer: c) Escherichia coli

3. Steps in Recombinant DNA Technology

  1. The enzyme that joins DNA fragments is:
    a) Restriction enzyme
    b) DNA ligase
    c) DNA polymerase
    d) Helicase
    Answer: b) DNA ligase
  2. Transfer of recombinant DNA into host cell is called:
    a) Translation
    b) Transformation
    c) Translocation
    d) Transcription
    Answer: b) Transformation
  3. Amplification of gene is done by:
    a) Ligation
    b) Transformation
    c) PCR
    d) Fermentation
    Answer: c) PCR

4. Polymerase Chain Reaction (PCR)

  1. PCR was developed by:
    a) Watson
    b) Crick
    c) Kary Mullis
    d) Mendel
    Answer: c) Kary Mullis
  2. The first step of PCR is:
    a) Annealing
    b) Extension
    c) Denaturation
    d) Ligation
    Answer: c) Denaturation
  3. Taq polymerase is obtained from:
    a) Virus
    b) Human cell
    c) Thermus aquaticus
    d) Yeast
    Answer: c) Thermus aquaticus
  4. Primers in PCR are:
    a) Enzymes
    b) Short DNA sequences
    c) Proteins
    d) Lipids
    Answer: b) Short DNA sequences

5. Bioreactors

  1. Bioreactors are used for:
    a) DNA cutting
    b) Large-scale production of products
    c) Gene mutation
    d) PCR
    Answer: b) Large-scale production of products
  2. The most commonly used bioreactor is:
    a) Airlift bioreactor
    b) Stirred tank bioreactor
    c) Test tube
    d) Flask
    Answer: b) Stirred tank bioreactor
  3. Bioreactors maintain optimal:
    a) Temperature and pH
    b) Gravity
    c) Sunlight
    d) Soil
    Answer: a) Temperature and pH

6. Downstream Processing

  1. Downstream processing involves:
    a) Cutting DNA
    b) Gene transfer
    c) Product purification
    d) PCR
    Answer: c) Product purification